From e5dc1e378619b11b296a953ca08abb2cdf38f9e0 Mon Sep 17 00:00:00 2001
From: Bastian Kersting <bkersting@google.com>
Date: Mon, 10 Mar 2025 08:59:24 +0000
Subject: [PATCH] Add comments for #[no_sanitize(cfi)] in stdlib

---
 library/std/src/sys/fs/unix.rs                       | 2 ++
 library/std/src/sys/pal/unix/fd.rs                   | 2 ++
 library/std/src/sys/pal/unix/process/process_unix.rs | 2 ++
 library/std/src/sys/pal/unix/thread.rs               | 2 ++
 library/std/src/sys/pal/unix/time.rs                 | 2 ++
 library/std/src/sys/pal/unix/weak.rs                 | 2 +-
 6 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/library/std/src/sys/fs/unix.rs b/library/std/src/sys/fs/unix.rs
index d95735978c1..d944bc9c9a2 100644
--- a/library/std/src/sys/fs/unix.rs
+++ b/library/std/src/sys/fs/unix.rs
@@ -1454,6 +1454,8 @@ impl File {
         Ok(())
     }
 
+    // FIXME(#115199): Rust currently omits weak function definitions
+    // and its metadata from LLVM IR.
     #[cfg_attr(
         any(
             target_os = "android",
diff --git a/library/std/src/sys/pal/unix/fd.rs b/library/std/src/sys/pal/unix/fd.rs
index 6da329288f7..a08c7ccec2d 100644
--- a/library/std/src/sys/pal/unix/fd.rs
+++ b/library/std/src/sys/pal/unix/fd.rs
@@ -251,6 +251,8 @@ impl FileDesc {
     }
 
     #[cfg(all(target_os = "android", target_pointer_width = "32"))]
+    // FIXME(#115199): Rust currently omits weak function definitions
+    // and its metadata from LLVM IR.
     #[no_sanitize(cfi)]
     pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
         super::weak::weak!(fn preadv64(libc::c_int, *const libc::iovec, libc::c_int, off64_t) -> isize);
diff --git a/library/std/src/sys/pal/unix/process/process_unix.rs b/library/std/src/sys/pal/unix/process/process_unix.rs
index 6d3680d231e..be9a7e91990 100644
--- a/library/std/src/sys/pal/unix/process/process_unix.rs
+++ b/library/std/src/sys/pal/unix/process/process_unix.rs
@@ -434,6 +434,8 @@ impl Command {
         target_os = "nto",
         target_vendor = "apple",
     ))]
+    // FIXME(#115199): Rust currently omits weak function definitions
+    // and its metadata from LLVM IR.
     #[cfg_attr(target_os = "linux", no_sanitize(cfi))]
     fn posix_spawn(
         &mut self,
diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
index 33db8e6939a..abe8d3fbf68 100644
--- a/library/std/src/sys/pal/unix/thread.rs
+++ b/library/std/src/sys/pal/unix/thread.rs
@@ -188,6 +188,8 @@ impl Thread {
     }
 
     #[cfg(any(target_os = "solaris", target_os = "illumos", target_os = "nto"))]
+    // FIXME(#115199): Rust currently omits weak function definitions
+    // and its metadata from LLVM IR.
     #[no_sanitize(cfi)]
     pub fn set_name(name: &CStr) {
         weak! {
diff --git a/library/std/src/sys/pal/unix/time.rs b/library/std/src/sys/pal/unix/time.rs
index fc60c307f34..c0a3044660b 100644
--- a/library/std/src/sys/pal/unix/time.rs
+++ b/library/std/src/sys/pal/unix/time.rs
@@ -96,6 +96,8 @@ impl Timespec {
         }
     }
 
+    // FIXME(#115199): Rust currently omits weak function definitions
+    // and its metadata from LLVM IR.
     #[cfg_attr(
         all(
             target_os = "linux",
diff --git a/library/std/src/sys/pal/unix/weak.rs b/library/std/src/sys/pal/unix/weak.rs
index 9a718b71f46..ce3f66a8374 100644
--- a/library/std/src/sys/pal/unix/weak.rs
+++ b/library/std/src/sys/pal/unix/weak.rs
@@ -144,7 +144,7 @@ unsafe fn fetch(name: &str) -> *mut libc::c_void {
 #[cfg(not(any(target_os = "linux", target_os = "android")))]
 pub(crate) macro syscall {
     (fn $name:ident($($arg_name:ident: $t:ty),*) -> $ret:ty) => (
-        // FIXME: Rust currently omits weak function definitions
+        // FIXME(#115199): Rust currently omits weak function definitions
         // and its metadata from LLVM IR.
         #[no_sanitize(cfi)]
         unsafe fn $name($($arg_name: $t),*) -> $ret {